Method and means for making bags



1944- c. TESSENDORF ET AL 2,364,009

METHOD AND MEANS FOR MAKING BAGS Filed Nov. 9, 1942 5 Sheets-Sheet l a WL/r we Z M Nov. 28, 1944- c. TESSENDORF ET AL 2,364,009

7 METHOD AND MEANS FOR MAKING BAGS Filed Nov. 9, 1942 5 Sheets-Sheet 21944' C. TESSENDORF ET AL METHOD AND MEANS FOR MAKING BAGS 5Sheeis-Sheet 3 Filed NOV. 9, 1942 y 9 W 5 m m3 2 a 4 [11'] 35; 2 f 0 "mQ M m ,7 :r E 9 w Patented Nov. 28, 1944 METHOD AND MEANS FOR MAKINGBAGS Charles Tessendorf, Neenah, and Frank J.

Gruper, In,

Menasha,

With, assignors to Marathon Corporation, a corporation of WisconsinApplication November 9, 1942, Serial No. 465,016

6 Claims.

This invention relates to a method and means for heat sealing bags. Morespecifically this invention relates to providing an open-ended tube witha heat-sealed seam by suitable application of heat and controlledrolling pressure followed by subsequent chilling and setting of the seamunder rolling pressure.

The packaging of dehydrated foods and other substances in non-metalliccontainers has been widely adopted recently owing to the convenience andefliciency of such packaging. In order to prevent access of moisture tothe contents in such packages which will cause deterioration of thecontents, it has been found that the packages must be securely andhermetically sealed. In making such packages from tubes or envelopes theproduction of seams which will not open or permit access of air andmoisture to the contents has. presented many difiiculties, particularlywhen the tubes are formed from sheet materials coated with aheat-scalable composition so as to permit formation of seamsautogenously by applying heat and pressure to the portions to be sealed.

According to the present invention the dimculties hitherto encounteredin forming effective heat-sealed seams have been successfully solved bycarefully controlling the conditions and sequence of steps in formingthe seams.

Further details of the invention will be more fully explained byreference to the drawings and specification.

Figure l is a perspective view of the tube sealing unit,

Figure 2 is an elevational view taken on lines 2-2 of Figure 1.

Figure 3 is a cross-sectional view taken on lines 33 of Figure 1,

Figure 4 is a sectional view taken on lines 44 of Figure 3,

Figure 5 is a sectional view of the heat-sealed tube taken along lines5-5 of Figure l,

Figure 6 is a sectional view taken on lines 6-6 of Figure 2,

Figure 7 is a sectional view taken on lines 1-! of Figure 2,

Figure 8 is a perspective view of the tube before sealing one endthereof, and

Figure 9 is a perspective view of the completed tube or bag, beingpartlycut away to show its sealed end.

Referring to the drawings, Figure 8 illustrates a tube Ill open at bothends made from any suitable sheet material such as paper, glassine,

Cellophane (regenerated cellulose), ethyl cellulose, cellulose acetateand the like and coated with a suitable heat-scalable coating on bothsurfaces or at least on its inner surface II which will form anautogenous seal by application of heat 'and pressure. Suitable coatingcompositions for this purpose are, for example, disclosed in Patent Nos.1,997,583 and 2,054,113. Any other suitable and available heat-sealablesheets may be utilized. The tube may be formed in any suitable manner byany conventional apparatus such as, for example, by continuously foldinga travelling web and sealing the overlapped portions by heat andpressure alone or by means of a suitable adhesive applied to theoverlapped longitudinal margins. The continuous tube so formed is thencut into open-ended tubes In of suitable dimension as illustrated inFigure 8. One end may be provided with a semi-circular cut-out portionl2 as a finger-grasping portion for facilitating opening of the tubeafter sealing same. The longitudinal side margins I3 and ll of the tubemay be subjected to heat and pressure to form autogenously sealedlongitudinal seams in order to reinforce the tube at the lateral marginsand to insure hermetic sealing of the contents. A bottom seam HI is thenformed as illustrated in Figure 9 in accordance with the presentinvention.

A spaced series of tubes ID are continuously fed to the sealingmechanism illustrated in Figure 1 forming the subject-matter of thisinven-- tion. The tubes l0 travel from the chute l6 onto an endlesstravelling conveyor belt l1 guided on rolls I8 and I9 supported in frame20, moving in the direction of the arrows indicated in Figure 1. Astheconveyor passes over roll l9 the tubes l0 fall onto an endlesstravelling conveyor 25 guided over rolls 26 and 21 moving in thedirection indicated by the arrows in Figure 1. The bottom portion of thetubes l0 contact a guide bar 28 which guides the tubes into properalignment with the bottom seam forming elements. The guide bar 28 isslightly inclined, say about 2, toward the line of travel of the tubesIII on conveyor 25.

The bottom seam forming elements comprise a large rotating supportingroll 30 on which a spaced series of the tubes ID are supported whiletravelling continuously. Roll 30 is driven by motor I through belt 2 andshaft 3. As the tubes l0 leave the conveyor 25 they are guided by curvedguide bar 29 and the bo'tom portions thereof which will form the seam 15are brought successively into direct contact with roll 30 at which pointendless belt 3| engages the successive tubes ill and carries them underrolling to control the pressure applied to the bags II pressure intocontact with roll 30. Belt 3| is supported on roll 60. Roll 80 ischilled in any carrled'over rolls 32, 33 and 3| which are posiplied tothe bottom portion of tube it for forming on eutogenousiy welded bottomseen It.

on the seams by means of pressure roll it which is adjustably positionedso as to apply predetermined pressure directly on belt 3| which in turnis firmly pressed against roll 30. Roll 35 is positioned about themiddle of the arc of travel or the tubes III on roll 30. The roll 30 isheated in any suitable manner. As shown in F'lgure '7, an internalarcuate stea'm jet 40 is provided internally 01 the roll 30 and steam issupplied to the j at through tube 1 l extent ding con- shaft 45. e out.through pi e .2 exaft the en or the 1 111g cnt1nu r a su.

re to body ortion of me tu 1s engage-a by 003. travelling belts so and IBelt is guided 5 1' rolls 34 and 52 and belt 5| is guided over rolls 5iand ii in the direction of the arrows as shown in Figure 2. The seamportion I5 01 the bags I'll is not engaged by belts 50 and 5| butextends freely and uncontacted beyond the belts during traveltherebetween in the relation shown in Figures 1 and 4. A blast of coldair is supplied by a blower 55 to chill the seam portion during thisportion of the travel, but without application of any pressure thereto.During travel of the bags between belts 50 and 5| the bags are flattenedinto substantially fiat planar condition.

The bags Ill are then conveyed into contact with a chilled supportingroll with the seam portion l5 in direct contact with roll 60. The bottomseams of the bags are retained under pressure against roll 60 by meansof endless belt 6| travelling in the direction of the arrows shown inFigure 2 coacting with about half of the periphery of roll 60. Belt 6|is supported on rolls 52, 62 and 63. Roll 62 is adjustably positioned soas to regulate the tension of belt 6| in Order suitable manner such asby cold circulating water which is sprayed internally as shown in Figure6. Cold water enters through pipe Ill and es. capes through sprayhead12. The water is with.

I drawn through tube 13 by a suction pump. Pipes 11 and 13 arestationary and extend through the shaft 16 supporting roll '60. Rolls 30and 60 are preferably of the same diameter and are synchronousiy' drivenby motor I through belts i andlasshowninligure 1.

and the adhesive finally set or congealed while subjected to rollingpressure and cold as they mechanism for Lung the with any After flnmformin n3 the tubes in an cuaee con- 8 and. app yin pre ure thereto toset the Sald scams.

2. Apparatus for formin bags from tubes of heat-scalable sheet materialwhich comprises a heated supporting roll and a spaced chilled supportingroll, guide means for aligning One end of said tubes with the heatedsupporting roll, an endless belt coacting with the periphery of saidsupporting roll to flex and apply pressure to said tubes for forming aseam while carried on said supporting roll, a pair of endless travellingbelts for receiving the tubes from said supporting roll and conveyingsaid tubes to said chilled supporting roll, and an endless belt coactingwith the periphery of said chilled roll to flex and apply pressure tosaid seams and convey the tubes on said supporting roll.

3. Apparatus for forming bags from tubes of heat-scalable sheet materialwhich comprises a conveyor for continuously feeding a plurality ofspaced tubes, a heated supporting roll and a spaced chilled supportingroll; guide means for aligning one end of said tubes with said heatedsupporting roll, an endless belt coacting with about half the peripheryof said Supp rting roll to flex and apply pressure to said tubes forforming a seam while carried on said supporting roll, a pair of endlesstravelling belts for receiving the tubes from said supporting roll andconveyingsaid tubes to said chilled supporting roll, and an endless beltcoacting with about half the pe- A riphery of said chilled roll to flexand apply pressure to said seams and convey the tubes on said supportingroll.

4. Apparatus for forming bags from tubes oi heat-scalable sheet materialwhich comprises a conveyor for continuously feeding a plurality ofspaced tubes, a heated supporting roll and a spaced chilled supportingroll, guide means for aligning one end of said tubes with said heatedsupporting roll, an endless belt coacting with the periphery of saidsupporting roll to flex and apply pressure to said tubes for iorming aseam while and convey the tubes on said supporting roll.

5. Apparatus for forming bags from tubes or .heat-sealable sheetmaterial which comprises a.

conveyor for continuously feeding a plurality orspacedtubeaaheatedsupportingrollanda spaced chilled supporting roll,guide means for aligning one end of said'tubes with said heatedmpporting roll, an endless belt coacting with the periphery of saidsupporting roll to flex and apcurrent of air against the seams whiletravelling plypnessuretosaidtubestoriorming-aseam while carried on saidsupporting roll, a pair oi endless travelling belts for receiving andengaging the body portion of the tubes from said supporting roll, andconveying said tubes to said chilled supporting roll, a blower fordirecting a with said pair of endless travelling belts, and an endlessbelt coacting with the periphery of said chilled roll to flex and applypressure to said seams and convey thetubes on said supporting roll.

6. Apparatus for formin bags from "tubes of heat-scalable sheet materialwhich comprises a conveyor for continuously feeding a plurality ofspaced tubes, a heated supporting roll and a spaced chilled supportingroll, guide means for aligningoneendofsaidtubeswithsaidheated supportingroll, an endless belt coacting with about half the periphery of saidsupporting roll toflex andapply pressuretosaidtubes forformingaseamwhilecarriedonsaidsupporflngmil,

e ollf ap ri s egulated asainstsaidendlessbeltwhileincontactwith.saidsupportingmlhapairotendlesstmvellingbeitsi'orreceivingthetubesfromsaidsmortingmllandconveyingsaidtubestosaidchilledsupporting roll, a blower for directing a currentofairagainsttheseamswhiletravellingwithsaidpairorendlessu-avellingbelmandanmdlessbeltcoactingwithabouthalttheperipheryotsaidchilledrolltoflexandapplypressuretosaidseamsandeonveythetubesonsaidsupportingroll. i

